Effect of titanium contamination on oxygen atom recombination probability on plasma conditioned surfaces

As the tolerances in gate dimensions in integrated circuit manufacturing become ever more stringent, plasma process conditions must be very tightly controlled. The reactor chamber wall contamination is one of the major causes of process drifts and is therefore of prime importance. Here, the authors report a study of the role of Ti contamination on an oxidized silicon surface in affecting the heterogeneous recombination coefficient of O in an O2 inductively coupled plasma reactor. Recombination coefficients were measured, using the spinning wall method, with in-situ Auger electron spectroscopy (AES) for surface analysis during plasma operation. The O-atom recombination coefficient on a Ti-free surface was found to be 0.034. After using an evaporation source to deposit a small amount of Ti on the spinning wall (17% of the atomic composition obtained from AES), the O recombination coefficient decreased to 0.022. A possible mechanism is proposed in which Ti reacts with ≡Si-O• sites that are active in recombin...

[1]  V. M. Donnelly,et al.  Interactions of chlorine plasmas with silicon chloride-coated reactor walls during and after silicon etching , 2012 .

[2]  Chang-I. Kim,et al.  Etch Properties of TiN Thin Film in Metal–Insulator–Metal Capacitor Using Inductively Coupled Plasma , 2011 .

[3]  V. Paraschiv,et al.  Impact of metal etch residues on etch species density and uniformity , 2010 .

[4]  V. M. Donnelly,et al.  Effect of Cu contamination on recombination of O atoms on a plasma-oxidized silicon surface , 2009 .

[5]  V. M. Donnelly,et al.  In-Situ Surface Recombination Measurements of Oxygen Atoms on Anodized Aluminum in an Oxygen Plasma , 2008 .

[6]  V. M. Donnelly,et al.  Mass and Auger electron spectroscopy studies of the interactions of atomic and molecular chlorine on a plasma reactor wall , 2008 .

[7]  N. Possémé,et al.  Analyses of chamber wall coatings during the patterning of ultralow-k materials with a metal hard mask: Consequences on cleaning strategies , 2007 .

[8]  V. M. Donnelly,et al.  Auger electron spectroscopy of surfaces during exposure to gaseous discharges , 2007 .

[9]  E. Pargon,et al.  Chemical analysis of deposits formed on the reactor walls during silicon and metal gate etching processes , 2006 .

[10]  V. M. Donnelly,et al.  Plasma-surface reactions at a spinning wall. , 2006, Physical Review Letters.

[11]  M. V. Malyshev,et al.  Characterization of transformer coupled oxygen plasmas by trace rare gases-optical emission spectroscopy and Langmuir probe analysis , 2000 .

[12]  X. Wallart,et al.  An Auger and electron energy‐loss study of reactions at the Ti‐SiO2 interface , 1991 .

[13]  G. Rubloff,et al.  Chemical bonding and reactions at Ti/Si and Ti/oxygen/Si interfaces , 1983 .